In the network trend of evolving to be based on IP, the traditional message service and the voice service are required to transfer to the IP-based next generation network. Standard groups of 3rd Generation Partnership Project (3GPP), 3GPP2 and Telecommunication and Internet Converged Service and Protocols for Advanced Networks (TISPAN) all consider the Session Initiation Protocol (SIP) as the basic protocol of the next core network. It has been a truth that the IP network applying the SIP is the network basis for service applications. In the background of the network convergence, a plurality of standard organizations has begun to research the converged service system.
The converged service system integrates various existing service functions, and can implement the practical experiences of users using services such as short messages, multimedia messages, email, and voice and so on. The converged service system does not mechanically implement the superposition of various services, but adopts a new architecture to implement the converged service experiences based on the next network. When a user uses services, the user only needs to pay attention to whether it is in an instant messaging way or not, but does not need to pay attention to which form of service is used. The converged service system can also support existing group services, including the group message and voice services, but there is not a particular implementation method yet.